Garden patio soakaway drainage

[pana37]

Hi all
I have a detached home I am looking at removing a raised patio and lifting crazy paving around 1 side and back of the house. currently has no rainwater drainage. The house roof rainwater drainage has 2 drainpipes one each side at the front of the house only!
I would like to install a soakaway in my garden with a channel drain, I believe it needs to be 5m away from the house.

My total garden dimensions are about 5.5m (from back of the house to fence x 11m wide so its quite shallow and wide some of this is grass which we will be keeping in some sort of form
the patio would be about 20m2 plus the slabs around the back and 1 side would ideally need to run into the soakaway. I live in Greater London so I guess it will be some clay around?

any advice would be appreciated
Thanks

 

[Hugh Jaleak]

I'd do a percolation test before anything else, to determine the suitability of the ground for a soakaway.

 

[TomSmith]

Hi, I would agree with Hugh and recommend that you undertake soakage testing to see if water naturally drains quick enough into the underlying soils beneath your garden before putting a soakaway in.

You mention you are in London therefore the likelihood is you'll be on London Clay, which doesn't drain very well. There are alternative drainage solutions you could consider if this the case.

However, if testing does show that water drains well in your garden you would need to locate any soakaway at least 5m away from building foundations or a road and 2.5m away from the garden boundary.